Potentially lethal failure

richgl1953

Yes it has the engine off when coasting but that wasn’t the cause of the problem according to BMW assist, this was complete shutdown

Ebe_Scrooge

Grumpy_chap said:

shiraz99 said:

richgl1953 said:

BMW X3 M sport mild hybrid

Does this have the Engine-off whilst coasting feature?

Wow - I just did an internet search and that's real.  

What - the engine turns off when you're coasting????  What happens to the power steering, servo-assisted brakes and such-like?  They won't work if the engine's not running.  I'm sure they've got a clever way around it - I'm genuinely curious, never heard of that before.

I was always taught it's very bad practice to coast in neutral - having the engine off has got to be even worse!

The_Fat_Controller

@Ebe_Scrooge it's a hybrid so those functions will be electrically powered.

Coasting is an entirely different event in hybrids !

Ebe_Scrooge

The_Fat_Controller said:

@Ebe_Scrooge it's a hybrid so those functions will be electrically powered.

Coasting is an entirely different event in hybrids !

Ah right, thanks.  I'll shut up now, I know nowt about hybrids :-)  

Grumpy_chap

Ebe_Scrooge said:

Grumpy_chap said:

shiraz99 said:

richgl1953 said:

BMW X3 M sport mild hybrid

Does this have the Engine-off whilst coasting feature?

Wow - I just did an internet search and that's real.  

What - the engine turns off when you're coasting????  What happens to the power steering, servo-assisted brakes and such-like?  They won't work if the engine's not running.  I'm sure they've got a clever way around it - I'm genuinely curious, never heard of that before.

I was always taught it's very bad practice to coast in neutral - having the engine off has got to be even worse!

I don't really know - I thought it was a humourous spoof suggestion until I searched, but it seems to be real "Coasting Function":
https://www.bmwmyanmar.com/en/topics/fascination-bmw/efficient-dynamics/energy-management.html

Herzlos

It's a hybrid though, so the engine isn't powering anything directly as I understand it. So the engine running or not has no impact on anything but propulsion and the battery. Given the car is coasting propulsion isn't needed and the battery won't be discharging much.  It's also kind of like stop/start in that the engine starts if any pedals are pressed.

shiraz99

@richgl1953, you didn't actually say what happened after the engine shut off, did your wife have to roll off the hard shoulder and come to a stop or was it a simple case of pressing the accelerator again and the engine starting up, or did she press the start/stop button?

unforeseen

Grumpy_chap said:

Ebe_Scrooge said:

Grumpy_chap said:

shiraz99 said:

richgl1953 said:

BMW X3 M sport mild hybrid

Does this have the Engine-off whilst coasting feature?

Wow - I just did an internet search and that's real.  

What - the engine turns off when you're coasting????  What happens to the power steering, servo-assisted brakes and such-like?  They won't work if the engine's not running.  I'm sure they've got a clever way around it - I'm genuinely curious, never heard of that before.

I was always taught it's very bad practice to coast in neutral - having the engine off has got to be even worse!

I don't really know - I thought it was a humourous spoof suggestion until I searched, but it seems to be real "Coasting Function":
https://www.bmwmyanmar.com/en/topics/fascination-bmw/efficient-dynamics/energy-management.html

Nothing new in that. The old Rover 90 had that. Also the Wartburgs in the late 60s/early 70s had what they called a fluid flywheel. Take your foot off the throttle and the engine disconnects from the gearbox and goes down to idle. There was a lever to put it into fixed wheel however it was a very lumpy drive then, probably due to the 3 cylinder 2-stroke engine

facade

unforeseen said:

Nothing new in that. The old Rover 90 had that. Also the Wartburgs in the late 60s/early 70s had what they called a fluid flywheel. Take your foot off the throttle and the engine disconnects from the gearbox and goes down to idle. There was a lever to put it into fixed wheel however it was a very lumpy drive then, probably due to the 3 cylinder 2-stroke engine

I think all the early P4s had it, the 90 my late father had didn't though, so it must have been a late model (HJX 742 if it is still in a barn or someones garage)

The two-stroke Saabs had it too, the idea was that if you used the engine as a brake it would seize up as no oil gets in with a closed throttle, probably the same for Wartburgs